Fireproof construction



No. 606,988. Patented July 5, I898.

A. DE MAN.

FIREPRUDF CONSTRUCTION.

(Application filed Feb. 2, 1898.)

(No Model.)

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ALPl-IONSE DE MAN, OF DETROIT, MICHIGAN.

FIREPROOF CONSTRUCTION.

SPECIFICATION forming part of Letters Patent No. 606,988, dated July 5,1898.

Application filed February 2, 1893. Serial No. 668,795. (No model.)

To all whom it may concern;

Be it known that I, ALPHONSE DE MAN, a citizen of the United States,residing at De troit, in the county of Wayne and State of Michigan, haveinvented certain new and useful Improvements in Fireproof Construction,of which the following is a-specification, reference being had thereinto the accompanying drawings.

My invention relates to the construction of composite slabs or spansespecially designed for fireproof-floor construction, and compris ing abody of artificial stone having metallic strengthening members embeddedtherein.

The invention consists, first, in the peculiar construction of metallicmembers employed for strengthening the slab, and, further, in thepeculiar construction of a composite slab or floor span in which thesemetallic members are employed.

In the drawings, Figure 1 is a perspective view of the metallicstrengthening member. Figs. 2 and 3 are views of modifications thereof.Fig. 4 is a plan showing the manner of forming the twists in saidstrengthening member. Fig. 5 is a plan View of a number of saidstrengthening members as arranged in position to receive theartificial-stone body. Fig. 6 is a longitudinal section through aportion of a composite slab complete. Fig. '7 is a cross-sectionthereof. Fig. 8 is a sectional view of afioor construction formed inaccordance with my invention.

The metallic strengthening members which I employ are formed of flat andcomparatively thin metallic bars A, preferably iron or steel. These barsare provided at intervals with laterally-deflected or partially-twistedsections B, preferably formed, as shown in Fig. 4, by placing the bar ingrooved or slotted heads 0 and D, separated from each other a distanceequal to the length of twist to be formed in the strengthening-bar, andthen engaging a fork or wrench E, with the center of the section of saidbar between said grooved heads, and giving a partial turn thereto. Thiswill form curved shoulders to, which when the bar is embedded in theartificial-stone body will form a firm hold or anchor and prevent theslipping of the bar.

I preferably twist the sections B to stand at the center at an angle ofabout ninety degrees to the main section of the bar, as shown in Fig. 1;but this is not necessary, as I may give a greater or lesser twist, asin the modifications shown in Figs. 2 and 3.

To form the composite slab or span, the strengthening bars, formed asabove described, are arranged in parallel relation to each other in asuitable mold or form with the main portion of the bars standing onedge--- that is, with the fiat side of adjacent bars parallel, as shownin Fig. 5. The artificial stone in a plastic state is then run in so asto fill the mold and completely surround the bars, thus forming acomposite slab, as shown in Figs. 6 and '7, the bars A furnishing therequired tensile strength to the slab and being preferably located inthe body in a position where the greatest tensile strain will beexerted, such as near the bottom surface of the slab.

The advantage of using thin fiat bars twisted at intervals only forforming the tension members is that they may be arranged on edge, asabove described, and with a given distance between centers of adjoiningbars a greater space is left for the artificial-stone body than withbars of the same strength, but of different cross-section. Thisfacilitates the tamping in of the plastic body between the bars andbeneath the twisted portions and insures perfect contact therewith, thusforming a perfect lock between the metallic member and the body andalso, on account of the greater mass of the body between the bars,preventing the same from cracking when subjected to strains.

Moreover, the bars themselves are much more rigid to withstand verticalstrains when of the shape described than if they were of a round orsquare cross-section and are also embedded a greater distance in thebody, and are thus better protected from the heat in case of fire.

In Fig. 8 I show a floor construction formed by laying bars A across thespace between two beams or girders and then filling in the body portionof artificial stone upon a suitable supporting moldboard, so as to formwhen complete a monolith floor the spans of which are given sufficienttensile strength by the bars A.

To hold the bars A in place during the proc ess of filling in theplastic material, I preferably provide them With hooks b at each endadapted to drop over the flange of the beam.

What I claim as my invention is A composite slab or span comprising abody of artificial stone and a plurality of metallic tension membersembedded therein, each consisting of a flat thin bar having twistsformed therein at intervals, said bars being arranged on edge side byside for the purpose described.

In testimony whereof I affix my signature in presence of two witnesses.

ALPIIONSE DE MAN.

\Vitnesses:

M. B. ODOG'HERTY, OTTO F. BARTHEL.

